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Pipeline preinstallation

Time : 2022-07-23 Hits : 6

1. Introduction to pipes

(1) Double line main and branch pipe: from the lubrication pump to the oil inlet of all dispensers, under relatively high pressure. Cold-drawn seamless steel tubes are usually made of no. 10 or 15 steel. Seriously rusted pipes should never be used;

(2) Feed pipe: from the distributor to all lubrication point oil inlet (bearing seat oil hole), the pressure is relatively low. Drawn copper tube is usually used to facilitate pipe distribution when bent. There are also cold-drawn seamless steel tube or stainless steel tube;

(3) When the active part is connected, the rubber hosefitting is used.

2. Pipe layout requirements

(1) Pipelines should try to avoid high temperature radiation and cooling water spray where the temperature is too high or too low, especially rubber hosefittings;

(2) The distribution should not affect the operation of the host and other equipment, and should be safe and reliable, convenient for work, observation and maintenance;

(3) The pipe should be horizontal, vertical, neat and beautiful. As far as possible less turning or small Angle bending pipe, the use of large arc, so as to reduce the resistance of oil flow;

(4) the installation of conflict, should be small tube to large tube, low pressure tube to high pressure tube;

(5) Pipelines should not touch each other when crossing, and should be separated from a certain distance;

(6) Thefittings of parallel pipelines should be stagger installed to avoid affecting installation and disassembly;

(7) In order to facilitate the disassembly and cleaning of the pipeline, live fittings should be properly installed, but they should be used less to reduce the possibility of leakage.

3. Determine pipe length

(1) Determine the length of the pipe on site according to the fixed piping path determined in 8.2, and pay attention to the influence of the radius of the elbow;

(2) To take into account the impact of all kinds of different pipe fittings into the pipeline;

(3) The length of the pipe should be determined, cut off and pre-installed, so as to facilitate on-site adjustment according to the actual situation. If all of the pipe is cut off at once, it will be difficult to pipe when the accumulated error occurs;

(4) Cut short pipes should be used as far as possible in each place where short pipes are needed. If necessary, straight pipefittings can be extended, but thefittings on the pipe section should be less than more.

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4. Cut off the pipe

(1) Use sawing machine or special pipe cutting machine to cut the pipe, and it is absolutely not allowed to use dissolving (such as flame cutting) or grinding wheel cutting;

(2) The incision should be smooth, the flatness of the section should not be greater than 1 mm, and the perpendicularity of the pipe axis should not be greater than 1 degree;

(3) Remove chips and burrs with file and scraper;

(4) Use clean compressed air or other methods to remove debris and rust attached in the tube;

5. Pipe is bent

(1) Cold bending with pipe bender, not hot bending (large caliber pipe can be replaced by right-anglefittings), bending radius should be more than 4 times the pipe diameter;

(2) The ellipticity at the bend (length and length diameter change) is less than 10% of the pipe diameter, and no wrinkle;

(3) If there is afittings at the bending pipe end, there should be a straight pipe connected with thefitting to avoid affecting installation;

6. Pipe and fittings welding

(1) GTAW or GTAW backfill welding. When the pressure exceeds 21mpa, argon gas of 5L /min should be pumped inside the tube at the same time.

(2) When the thickness of the pipe wall is greater than 2mm, the outer circle should be cut into 35° bevels, and a gap of 3mm should be left at the matchingfittings; When the thickness of the pipe wall is less than or equal to 2mm, the groove shall not be cut and a 2mm gap shall be left at the counterpart;

(3) The pipe axis must coincide, the amount of staggered side is less than 15% of the wall thickness, and the deviation slope is less than 1:200;

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7. Installation of pipe clamp

(1) The backing plate of the pipe clamp is generally welded to the structural parts directly or through brackets such as Angle steel, and the bracket is fixed with expansion bolts on the concrete floor surface or wall side;

(2) When installing the pipe clamp, pay attention to leveling, that is, the installation surface is at the same height;

(3) pipe clamp spacing: about 0.5~ 1m when diameter ≤φ10; Diameter φ10~25 about 1~1.5 meters; Diameter φ25~50 about 1.5~2 meters, but in the right Angle corner, each side should use a pipe clamp.

8. Pre-installed

(1) Connect the pipefittings with the equipment and the pipe with the pipefittings segment by segment until all the pre-installation is completed;

(2) At the same time, the pipe clamp plate shall be welded to the structural part or bracket, and the pipe shall not be welded to the pipe clamp or bracket;

(3) After the pre-installation is completed and the inspection is qualified, print the matching mark for the pipeline, one piece and one number, and list them in a table for use. After the pipeline is removed and cleaned, restore it according to the serial number.

9. Precautions

(1) Before installation, all steel pipes can be pickled according to the requirements of Chapter 9, especially the steel pipes connected with the sleeve type pipefittings should be pickled first, and then the sleeve should be pre-fastened at the pipe end;

(2) All pipefittings should be cleaned with kerosene before installation, and the O-ring inside should be temporarily removed for storage, and then put on before formal installation;

(3) During construction, the oil port, pipefittings, pipe end and other opening of pump, distributor and other equipment should be kept clean, and foreign bodies such as water and dust should not be allowed to enter;

(4) Pipelines shall be laid in a free state. After welding, excessive radial force shall not be applied to fix and connect pipelines forcibly;

(5) The oil hole of the bearing seat should be checked in advance, the internal oil circuit is smooth, and the oil thread is matched with thefittings

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